This application claims the benefit of the filing date of Taiwan Application Ser. No. 092217157, filed Sep. 24, 2003, the content of which is incorporated herein by reference.
The invention relates to a flatbed scanner, and more particularly to a flatbed scanner with a short border such that a to-be-scanned book can completely attached to and completed supported by the flatbed scanner.
A scanner, copier and the like use an optical module to acquire an image of a to-be-scanned document. Various document support structures for supporting the to-be-scanned document as disclosed in, for example, Taiwan Patent Publication Nos. 364710, 477510, 484776 and 481405 have been developed and used. For example, in the conventional document support structures of the flatbed scanners, when the user wants to acquire the image of a book, the central binding portion C of the book B of FIG. 1 cannot smoothly contact the glass plate 12 of the flatbed scanner because the limitation of the housing 11. Thus, when the optical module OS scans the book B, the scanned image may have shadows and deformations at the central binding portion C of the book B because the optical path OT cannot reach the central binding portion C of the book B.
Taiwan Patent Publication No. 364710 discloses an upper housing of a flatbed scanner, in which a fastener at a side and three resilient fasteners at three sides are used to fasten the glass plate. In this case, the reliability is insufficient, and an auxiliary tape or other fixing members have to be used in order to prevent the glass plate from falling down. In addition, when the image of the book is scanned according to this structure, the optical path cannot reach the central binding portion of the book when the optical module is scanning because a gap is left between the book's central binding portion and the glass plate of the flatbed scanner. Hence, the scan result includes shadows, deformations and the like at the book's central binding portion.
Taiwan Patent Publication No. 477510 discloses a fixing structure for fixing a glass plate of a scanner using a fastener at a side and a plurality of ribs and a cam-link mechanism. According to this structure, when the image of the book is scanned, the optical path of the optical module cannot reach the book's central binding portion because a gap is left between the book's central binding portion and the glass plate of the flatbed scanner owing to the existence of the ribs. Hence, the scanned result includes shadows, deformations, and the like at the book's central binding portion. In addition, this structure has to use more members, so the assembly is complicated and the manufacturing cost is high.
Taiwan Patent Publication No. 484776 discloses a supporting mechanism for a glass plate of a scanner, wherein an inverse-U shaped sliding slot is used to fix the glass plate. According to this structure, when the book's image is scanned, the optical path of the optical module cannot reach the book's central binding portion owing to the step between the sliding slot and the glass plate. Hence, the scan result includes shadows, deformations and the like at the book's central binding portion.
Taiwan Patent Publication No. 481405 discloses a simple device for fixing a glass plate without adhesive, in which a plurality of seats is formed at four corners of the supporting mechanism and a plurality of projecting plates are formed at four edges to fixing the glass plate. According to this structure, when the book's image is scanned, the optical path of the optical module cannot reach the book's central binding portion because a step exists between the projecting plates and the glass plate. Hence, the scanned result includes shadows, deformations, and the like at the book's central binding portion. As shown in FIG. 5 of this Taiwan patent, if the glass plate interferes with the seat and is then pressed into the seat (the two sides of the glass plate of FIG. 5C have reach the seat) when the glass plate is placed down, it means that the seat also has the property of resilient fixing property (the resilience of the glass plate is extremely poor), and the problem of insufficient reliability in the 364710 patent still exists in the 481405 patent. If the glass plate can be directly put into the seat without interfering with the seat when the glass plate is placed down, it is doubtful as to the actual reliability of preventing the glass plate from falling down using the anti-slip sheet during the transportation procedure (because it claims that no tape or other fixing member has to be used).